The invention is concerned with a torque sensor, in particular for electric steering mechanisms.
Such torque sensor is known from Norton, U.S. Pat. No. 4,548,091. This patent has an inductively operating torque sensor with two input elements and an annular output element connected to the input elements by a series of connecting elements and reinforcing arms with articulated connections. The construction is very expensive and has a relatively big outside diameter which results from the installation of a large number of complicated individual parts. Constructing a series of torque sensors out of such elements is not possible since so doing would cut the sensor's twisting rigidity in half.
The object of the invention is to avoid the disadvantages inherent in Norton and to provide a torque sensor of small size and ease of manufacture. A series of sensors should be possible without affecting the torsional characteristics.
A technical article of "Machine Design" of Apr. 14, 1966 (V903) shows a sleeve of magnetically permeable material having ring flanges at its ends secured to a torque bar. The sleeve has a central ring flange in between the end ring flanges on each side.
There is an arrangement of bores connected by slots slanted at 45.degree. in the sleeve between each ring and the center ring.
The slots at one side of the center ring are slanted oppositely from that on the other side to result in a relative 90.degree. angular relationship.